This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The plasma form of human platelet activating factor acetylhydrolase (pPAFAH) functions by reducing PAF levels as a general anti-inflammatory scavenger and is linked to anaphylactic shock, asthma and allergic reactions. As a membrane associated protein with no known homologues, pPAFAH is a worthy structural target. Recently we have published the crystal structure of this important enzyme and shown how enzyme binds to LDL interface during catalysis. Data collected from 24ID would be used to solve the crystal structures of pPAFAH complex with sarin and soman and useful to predict the mode of substrate binding to the enzyme and hydrolysis of toxic organophosphates. PDB codes for the complex structures for which data collected at 24ID are 3F96 and 3F97 for sarin and soman, respectively.